Biogeochemical Cycles

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1International Capital Flows and Boom-Bust Cycles in the Asia Pacific Region + Soyoung Kim* University of Illinois at Urbana-Champaign and Korea University Sunghyun H. Kim** Tufts University Yunjong Wang*** SK Research Institute Abstract This paper documents evidence of business cycle synchronization in selected Asia Pacific countries in the 1990s. We explain business cycle synchronization by the channel of international capital flows. Using the VAR method, we find that most Asian countries experience boom-bust cycles following capital inflows, where the boom in output is mostly driven by consumption and investment. Empirical evidence shows that capital flows in the region are highly correlated, which supports the conclusion that capital market liberalization has contributed to business cycle synchronization in Asia. We also find that business cycles in the Asian crisis countries are highly synchronized with those in Japan. JEL Classification: F02, F36, F41 Key words: business cycle synchronization, capital flows, boom-bust cycles, financial integration. + We are grateful to Gordon de Brouwer, Barry Eichengreen, Takeo Hoshi, Takatoshi Ito, Eiji Ogawa, and Yung Chul Park for their helpful comments and suggestions. This research was kindly supported by a Ford Foundation grant. * Department of Economics, University of Illinois at Urbana-Champaign, DKH, 225b, 1407 W. Gregory Drive, Urbana, IL 61801. ** Corresponding Author. Department of Economics, Tufts University, Medford MA 02155. Tel: 617-627-3662, Fax: 617-627-3917, E-mail: Sunghyun.Kim@tufts.edu. *** SK Research Institute, 14th Floor, Seoul Finance Center, 84 Taepyungro 1-ga, Seoul 100-101, Korea. 21. Introduction Over the past decade, a number of Asia Pacific countries have liberalized their financial markets to foreign capital by reducing restrictions on inward and outward capital flows. Increased capital flows due to financial integration can generate substantial effects on business cycles. Large capital inflows following financial market liberalization can generate an initial surge in investment and asset price bubbles followed by capital outflows and recession, the so-called boom-bust cycles. In worst cases, the boom-bust cycles can end with a sudden reversal of capital flows and financial crises.1 On the other hand, by allowing domestic residents to engage in international financial asset transactions, financial market opening can reduce the volatility of some macroeconomic variables such as consumption through risk-sharing.2 What are the macroeconomic effects of capital flows, in particular on business cycle fluctuations? Do business cycles become less volatile and more synchronized across countries as the degree of financial integration increases? Understanding the business cycle implications of capital flows is important as it can also reveal a great deal about the welfare implications of financial market liberalization policies as well as international monetary arrangements. This paper focuses on the effects of capital flows due to financial market liberalization on business cycles, Biogeochemical Cycles Biogeochemical Cycles Bởi: OpenStaxCollege Energy flows directionally through ecosystems, entering as sunlight (or inorganic molecules for chemoautotrophs) and leaving as heat during the transfers between trophic levels Rather than flowing through an ecosystem, the matter that makes up living organisms is conserved and recycled The six most common elements associated with organic molecules—carbon, nitrogen, hydrogen, oxygen, phosphorus, and sulfur—take a variety of chemical forms and may exist for long periods in the atmosphere, on land, in water, or beneath Earth’s surface Geologic processes, such as weathering, erosion, water drainage, and the subduction of the continental plates, all play a role in the cycling of elements on Earth Because geology and chemistry have major roles in the study of this process, the recycling of inorganic matter between living organisms and their nonliving environment is called a biogeochemical cycle Water, which contains hydrogen and oxygen, is essential to all living processes The hydrosphere is the area of Earth where water movement and storage occurs: as liquid water on the surface (rivers, lakes, oceans) and beneath the surface (groundwater) or ice, (polar ice caps and glaciers), and as water vapor in the atmosphere Carbon is found in all organic macromolecules and is an important constituent of fossil fuels Nitrogen is a major component of our nucleic acids and proteins and is critical to human agriculture Phosphorus, a major component of nucleic acids, is one of the main ingredients (along with nitrogen) in artificial fertilizers used in agriculture, which has environmental impacts on our surface water Sulfur, critical to the three-dimensional folding of proteins (as in disulfide binding), is released into the atmosphere by the burning of fossil fuels The cycling of these elements is interconnected For example, the movement of water is critical for the leaching of nitrogen and phosphate into rivers, lakes, and oceans The ocean is also a major reservoir for carbon Thus, mineral nutrients are cycled, either rapidly or slowly, through the entire biosphere between the biotic and abiotic world and from one living organism to another Concept in Action 1/17 Biogeochemical Cycles Head to this website to learn more about biogeochemical cycles The Water Cycle Water is essential for all living processes The human body is more than one-half water and human cells are more than 70 percent water Thus, most land animals need a supply of fresh water to survive Of the stores of water on Earth, 97.5 percent is salt water ([link]) Of the remaining water, 99 percent is locked as underground water or ice Thus, less than one percent of fresh water is present in lakes and rivers Many living things are dependent on this small amount of surface fresh water supply, a lack of which can have important effects on ecosystem dynamics Humans, of course, have developed technologies to increase water availability, such as digging wells to harvest groundwater, storing rainwater, and using desalination to obtain drinkable water from the ocean Although this pursuit of drinkable water has been ongoing throughout human history, the supply of fresh water continues to be a major issue in modern times Only 2.5 percent of water on Earth is fresh water, and less than percent of fresh water is easily accessible to living things The various processes that occur during the cycling of water are illustrated in [link] The processes include the following: • • • • • evaporation and sublimation condensation and precipitation subsurface water flow surface runoff and snowmelt streamflow 2/17 Biogeochemical Cycles The water cycle is driven by the Sun’s energy as it warms the oceans and other surface waters This leads to evaporation (water to water vapor) of liquid surface water and sublimation (ice to water vapor) of frozen water, thus moving large amounts of water into the atmosphere as water vapor Over time, this water vapor condenses into clouds as liquid or frozen droplets and eventually leads to precipitation (rain or snow), which returns water to Earth’s surface Rain reaching Earth’s surface may evaporate again, flow over the surface, or percolate into the ground Most easily observed is surface runoff: the flow of fresh water either from rain or melting ice Runoff can make its way through streams and lakes to the oceans or flow directly to the oceans themselves In most natural terrestrial environments rain encounters vegetation before it reaches the soil surface A significant percentage of water evaporates immediately from the surfaces of plants What is left reaches the soil and begins to move down Surface runoff will occur only if the soil becomes saturated with water in a heavy rainfall Most water in the soil will be taken up by plant roots The plant will use some of this water for its own metabolism, and some of that will find its way into animals that eat the plants, but much of it will be lost ... I NTERNATIONAL J OURNAL OF E NERGY AND E NVIRONMENT Volume 3, Issue 5, 2012 pp.715-730 Journal homepage: www.IJEE.IEEFoundation.org ISSN 2076-2895 (Print), ISSN 2076-2909 (Online) ©2012 International Energy & Environment Foundation. All rights reserved. Exergy analysis for combined regenerative Brayton and inverse Brayton cycles Zelong Zhang, Lingen Chen, Fengrui Sun College of Naval Architecture and Power, Naval University of Engineering, Wuhan 430033, China. Abstract This paper presents the study of exergy analysis of combined regenerative Brayton and inverse Brayton cycles. The analytical formulae of exergy loss and exergy efficiency are derived. The largest exergy loss location is determined. By taking the maximum exergy efficiency as the objective, the choice of bottom cycle pressure ratio is optimized by detailed numerical examples, and the corresponding optimal exergy efficiency is obtained. The influences of various parameters on the exergy efficiency and other performances are analyzed by numerical calculations. Copyright © 2012 International Energy and Environment Foundation - All rights reserved. Keywords: Regenerative Brayton cycle; Inverse Brayton cycle; Exergy analysis; Exergy loss; Exergy efficiency; Optimization. 1. Introduction Nowadays, in order to meet the demands of energy-saving and environmental protection, people want to construct new energy and power plants which could gain better performance. Because of their high efficiency and advances in the technologies of the individual components, combined-cycle power plants have been applied widely in recent years. Steam and gas turbine combined cycles are considered the most effective power plants [1]. The thermal efficiency of these cycle types exceeded 55 percent several years ago and is now at approximately 60 percent. Also these cycle types’ application is becoming more and more common in mid and large scale power production due to their high efficiency and reliability. In order to increase the power output, a hybrid gas turbine cycle (Braysson cycle) was proposed based on a conventional Brayton cycle for the high temperature heat addition process and Ericsson cycle for the low temperature heat rejection process, and the first law analysis of the Braysson cycle was performed by Frost et al. [2] in 1997. Furthermore, the exergy analysis of the Braysson cycle based on exergy balance was performed by Zheng et al. [3] in 2001. Fujii et al. [4] studied a combined-cycle with a top cycle (Brayton cycle) and a bottom cycle consisting of an expander followed by an inter-cooled compressor in 2001. They found that when fixed the bottom cycle pressure ratio to 0.25 bar could avoid a rapid increase in gas flow axial velocity effectively. They also proposed the use of two parallel inverse Brayton cycles instead of one in order to reduce the size of the overall power plant. Bianchi et al. [5] examined a combined-cycle with a top cycle (Brayton cycle) and a bottom cycle (an inverted Brayton cycle in which compress to atmospheric pressure) in 2002. Agnew et al. [6] proposed combined Brayton and inverse Brayton cycles in 2003, and performed the first law analysis of the combined cycles. They indicated that the optimal expansion pressure of the inverse Brayton cycle is 0.5 bar for optimum performance. The exergy analysis and optimization of the combined Brayton and inverse Brayton cycles were I NTERNATIONAL J OURNAL OF E NERGY AND E NVIRONMENT Volume 4, Issue 1, 2013 pp.93-102 Journal homepage: www.IJEE.IEEFoundation.org ISSN 2076-2895 (Print), ISSN 2076-2909 (Online) ©2013 International Energy & Environment Foundation. All rights reserved. Exergoeconomic performance optimization for a steady- flow endoreversible refrigeration model including six typical cycles Lingen Chen, Xuxian Kan, Fengrui Sun, Feng Wu College of Naval Architecture and Power, Naval University of Engineering, Wuhan 430033, P. R. China. Abstract The operation of a universal steady flow endoreversible refrigeration cycle model consisting of a constant thermal-capacity heating branch, two constant thermal-capacity cooling branches and two adiabatic branches is viewed as a production process with exergy as its output. The finite time exergoeconomic performance optimization of the refrigeration cycle is investigated by taking profit rate optimization criterion as the objective. The relations between the profit rate and the temperature ratio of working fluid, between the COP (coefficient of performance) and the temperature ratio of working fluid, as well as the optimal relation between profit rate and the COP of the cycle are derived. The focus of this paper is to search the compromised optimization between economics (profit rate) and the utilization factor (COP) for endoreversible refrigeration cycles, by searching the optimum COP at maximum profit, which is termed as the finite-time exergoeconomic performance bound. Moreover, performance analysis and optimization of the model are carried out in order to investigate the effect of cycle process on the performance of the cycles using numerical example. The results obtained herein include the performance characteristics of endoreversible Carnot, Diesel, Otto, Atkinson, Dual and Brayton refrigeration cycles. Copyright © 2013 International Energy and Environment Foundation - All rights reserved. Keywords: Finite-time thermodynamics; Endoreversible refrigeration cycle; Exergoeconomic performance 1. Introduction Recently, the analysis and optimization of thermodynamic cycles for different optimization objectives has made tremendous progress by using finite-time thermodynamic theory [1-14]. Finite-time thermodynamics is a powerful tool for the performance analysis and optimization of various cycles. For refrigeration cycles, the performance analysis and optimization have been carried out by taking cooling load, coefficient of performance (COP), specific cooling load, cooling load density, exergy destruction, exergy output, exergy efficiency, and ecological criteria as the optimization objectives in much work, and many meaningful results have been obtained [15-27]. A relatively new method that combines exergy with conventional concepts from long-run engineering economic optimization to evaluate and optimize the design and performance of energy systems is exergoeconomic (or thermoeconomic) analysis [28, 29]. Salamon and Nitzan’s work [30] combined the endoreversible model with exergoeconomic analysis. It was termed as finite time exergoeconomic analysis [31-45] to distinguish it from the endoreversible analysis with pure thermodynamic objectives and the exergoeconomic analysis with long-run economic optimization. Similarly, the performance International Journal of Energy and Environment (IJEE), Volume 4, Issue 1, 2013, pp.93-102 ISSN 2076-2895 (Print), ISSN 2076-2909 (Online) ©2013 International Energy & Environment Foundation. All rights Note Biogeochemical cycles in forests of the "Sierra de Béjar" mountains (province of Salamanca, Spain): decomposition index of the leaf litter I Santa Regina JF Gallardo Consejo Superior de Investigaciones Cientificas, Aptado 257, CSIC, Salamanca 37071, Spain (Received 7 February 1994; accepted 26 September 1994) Summary — Both leaf and total litter decomposition indices were established in 3 forest ecosystems of the "Sierra de Béjar" mountains: a climax Quercus pyrenaica Willd oak forest, a paraclimax Castanea sativa Miller sweet-chestnut coppice, and a disclimax Pinus sylvestris L Scots pine forest. Higher decomposition rates and higher Jenny’s decomposition indices were observed in the chesnut leaves than in the oak and pine leaves. Under almost identical climatic conditions, chesnut leaves decomposed faster than those of oak and Scots pine. Thus, litter accumulation was highest in the pine forest, followed by the oak and chestnut forests. litter decomposition / forest ecosystems / biogeochemical cycles Résumé — Cycles biogéochimiques dans 3 forêts de la Sierra de Béjar (province de Sala- manque, Espagne) : indices de décomposition de la litière. Les indices de décomposition de la litière et des feuilles ont été déterminés dans 3 forêts de la Sierra de Béjar (province de Salamanque, Espagne) : une chênaie à Quercus pyrenaica Willd, une châtaigneraie à Castanea sativa Miller et une pineraie à Pinus sylvestris L. Les valeurs des indices les plus élevés sont rencontrées dans la châ- taigneraie, tandis que la plus grande accumulation de litière se trouve dans la pineraie, bien que les condi- tions climatiques soient similaires. décomposition de la litière / écosystème forestier / cycle biogéochimique * Correspondence and reprints INTRODUCTION The mineralization of the humus and the release of nutrients from the leaf litter is a fundamental process in the bioelement dynamics of the forest ecosystems (Vogt et al, 1986). This key role of the organic mat- ter decomposition for the mineral nutrition of the plant has been well documented (Swift et al, 1979; Berg and Theander, 1984; Santa Regina, 1987). In a forest ecosystem in equilibrium, a relationship has been suggested between the amount of litter reaching the forest floor annually, and the amount of organic matter decomposed on the soil surface over the same period of time, and the ratio (decom- position index) could be an ecological char- acteristic (Jenny et al, 1949). More recent studies have found a correlation between the apparent litter mass loss with the actual evapotranspiration (AET, Dyer et al, 1990), either other related soil-climate parameters (Berg et al, 1990) at the northern hemi- sphere scale. The aim of this study was to estimate the litter decomposition rates, using the litter- bag method (Bocock and Gilbert, 1957), in 3 types of forests and also in a grass meadow, and to compare the results with the amount of quasi-permanent litter on the soils of these 3 types of forests. Site description Three permanent plots were chosen in the Sierra de Béjar area (south-east of the province of Salamanca, Spain): i) a climax oak (Quercus pyrenaica Willd) forest about 60 years old after clear cutting; ii) a chestnut (Castanea sativa Miller) coppice about 15 years old after the last harvest; and iii) a Scots pine (Pinus sylvestris L) forest about 30 years old after new planting: The climate of the study area is humid mediterranean, with mean temperature about 11.5°C and Biogeochemical Cycles Elemental cycles that affect ecosystems Time for decomposition Biogeochemical Cycles Carbon – greenhouse gases Nitrogen – acid rain, nutrient Phosphorus - nutrient Sulfur – acid rain Oxygen - ozone C C numbers are billions of metric tons C Carbon dioxide concentrations are lower near trees during midday because trees having been “eating” the CO2 Carbon dioxide concentrations are high near the forest floor, where decomposers work around the clock during the growing season C Carbon dioxide production is highest during the growing season when decomposers are busiest N S Less land in the S hemisphere means both less seasonal difference in CO concentrations Oceans in the S have only a little phytoplankton, which neither uses nor produces much CO2, so there are no seasonal ups and downs Seasonal swings over land in the N are much bigger N N 3.9x106 Gt ~7 Gt ~100 Gt Table of nitrogen cycle processes N Process Fixation Mineralization/ Ammonification Nitrification Denitrification Starts with N2 gas Amino acids Ammonia to nitrite then to Nitrates Ends with Ammonia NH3 Ammonia NH3 Nitrate N2 gas End used by Nitrifying bacteria Nitrifying bacteria Plants Who does it most fixed by nitrogen-fixing bacteria associated with legumes and other plants, as well as free-living bacteria, cyanobacteria some fixed by lightning, cosmic radiation decomposer bacteria and fungi breaking down organic compounds that contain nitrogen (proteins) Nitrifying bacteria: one group of bacteria for each stage (Nitrosomonas, Nitrobacter) Nitrogen-fixing & other bacteria cyanobacteria facultatively anaerobic fungi and bacteria (Pseudomonas) N Nitrogen fixed from the atmosphere and mineralized during decomposition becomes available to living things as ammonia – NH3 or ammonium ion – NH4+ The plants would be happy to take up ammonia, but soil bacteria that don’t want the nitrogen, just the hydrogen ions, usually turn the ammonia into nitrate ions (N03-) by nitrification before the plants can use it The bacteria, being in the soil, are in the right place to grab the ammonia first Plants take up ammonia (if they can get it) and nitrate by assimilation and use it to make proteins, and animals may eat the plants and either use the nitrogen for proteins, or excrete it in urine Nitrogen in nitrate that plants don’t take up can be returned to the atmosphere as N2 gas through denitrification N S S S P P ... natural biogeochemical cycles due to pollution, oil spills, and events causing global climate 15/17 Biogeochemical Cycles change The health of the biosphere depends on understanding these cycles. . .Biogeochemical Cycles Head to this website to learn more about biogeochemical cycles The Water Cycle Water is essential for all living... [link] 4/17 Biogeochemical Cycles Carbon dioxide gas exists in the atmosphere and is dissolved in water Photosynthesis converts carbon dioxide gas to organic carbon, and respiration cycles the